add fancy @modifier decorator

pystache/template.py

@@ -1,6 +1,21 @@
 import re
 import cgi
 
+modifiers = {}
+def modifier(symbol):
+    """Decorator for associating a function with a Mustache tag modifier.
+
+    @modifier('P')
+    def render_tongue(self, tag_name=None, context=None):
+        return ":P %s" % tag_name
+
+    {{P yo }} => :P yo
+    """
+    def set_modifier(func):
+        modifiers[symbol] = func
+        return func
+    return set_modifier
+
 class Template(object):
     # The regular expression used to find a #section
     section_re = None
@@ -14,15 +29,6 @@ class Template(object):
     # Closing tag delimiter
     ctag = '}}'
 
-    # Names of different tag modifiers, used to render them.
-    tag_types = {
-        None: 'tag',
-        '!': 'comment',
-        '{': 'unescaped',
-        '>': 'partial',
-        '=': 'delimiter'
-    }
-
     def __init__(self, template, context=None):
         self.template = template
         self.context = context or {}
@@ -79,26 +85,28 @@ class Template(object):
 
             tag, tag_type, tag_name = match.group(0, 1, 2)
             tag_name = tag_name.strip()
-            func = 'render_' + self.tag_types[tag_type]
-
-            if hasattr(self, func):
-                replacement = getattr(self, func)(tag_name, context)
-                template = template.replace(tag, replacement)
+            func = modifiers[tag_type]
+            replacement = func(self, tag_name, context)
+            template = template.replace(tag, replacement)
 
         return template
 
+    @modifier(None)
     def render_tag(self, tag_name, context):
         """Given a tag name and context, finds, escapes, and renders the tag."""
         return cgi.escape(context.get(tag_name, ''))
 
+    @modifier('!')
     def render_comment(self, tag_name=None, context=None):
         """Rendering a comment always returns nothing."""
         return ''
 
+    @modifier('{')
     def render_unescaped(self, tag_name=None, context=None):
         """Render a tag without escaping it."""
         return context.get(tag_name, '')
 
+    @modifier('>')
     def render_partial(self, tag_name=None, context=None):
         """Renders a partial within the current context."""
         # Import view here to avoid import loop
@@ -109,6 +117,7 @@ class Template(object):
 
         return view.render()
 
+    @modifier('=')
     def render_delimiter(self, tag_name=None, context=None):
         """Changes the Mustache delimiter."""
         self.otag, self.ctag = tag_name.split(' ')